Cotton fabric having a linenlike finish resistant to wear and washing



Patented Dec. 8, 1925.

STATES EDGAR RAYMOND CLARK, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 MILTON S. -ERLANGER, OF NEW YORK, N. Y.

COTTON FABRIC HAVING A LINENLIKE FINISH RESISTANT TO WEAR AND WASHING.

No Drawing.

To all whom it may concern:

Be it known that I, EDGAR RAYMOND CLARK, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny, State of Pennsylvania, have invented certain new and useful ,Improvements in Cotton Fabrics Having a Linenlike Finish Resistant to Wear and Washing; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in the treatment of cotton fabrics whereby the treated fabric is given a permanent linenlike appearance and feel, and includes the improved fabric itself as Well as the method of its production.

One of the primary objects of the invention is to roduce table damask having a linen-like finish, but the invention is applicable to other cotton fabrics where a linen-like finish is desired.

The new fabric of the present invention is a soft, pliable and linen-like fabric, having a linen-like appearance and feel and capable of withstanding repeated laundering. The new fabric has permanently and integrally combined therewith cellulose regenerated from viscose applied to the fabric by a special method of application.

According to the present invention the cotton, fabric is treated with a suitable viscose solution, the excess solution removed by pressure, and the viscose then decomposed and cellulose regenerated 'or precipitated therefrom on and in the fibre of the fabric, as more fully hereinafter ex lained.

The viscose solution employed in t e process may be made from cotton rags, linters, cellulose from wood, etc. Bleached cotton linters are well adapted for use. These should be in good chemical condition, that is, free from oxycellulose and other products resulting from the action of chemicals on cellulose, and also free from dirt, oil and leaf or seed particles. In making the viscose solution I keep the alkalinity low Application filed March 1, 1923. Serial No. 622,223.

so that the resulting viscose solution will be of medium or low alkalinity, such as is prodin-ed for example by using not morethan two molecular equivalents of sodium hydroxide to'one of cellulose. 'When inferior forms of cellulose are used in making the viscose solution, the solution may be purified before it is applied to the fabric. By the use of a viscose solution of low alkalinity, and suitably prepared, discoloration of the fabrics is avoided during the drying operation to which they are subjected.

The following specific example illustrates onemethod of preparing a viscose solution particularly ada ted for use in the treatment of cotton fa rics according to the present invention; but it Will be understood that the invention is not limited to the preparation of the viscose solution in this particular way, although, as above indicated, the preparation and use of a viscose solution of low alkalinity is of advantage in the practice of the invention; and I consider the production of a v iscose solution of 10W alkalinity in this way to be itself new, and a part of the invention:

100 lbs. of air dry bleached cotton'linters, free from dirt, oil, leaf or seed particles, and also free from any of the Various products which may result from over-bleaching of such materials, are wet with an excess, say gallons, of caustic soda solution of specific gravity 1.255 at 60 F., containing 20% of sodium hydroxide. The cellulosic material and the caustic soda solution are stirred together for one hour and themass is then pressed to remove the excess alkali. The pressure is so regulated that the squeezed out mass weighs 350 lbs. ThlS mass is then loosened, spread in 0 en vessels of shallow depth and allowe to age for approximately 24 hours, during whlch time it should be turned over from time to time to permit of access of air to all the particles. This product is then kneaded with 50 lbs. of carbon disulphide in a. closed mixer of suitable construction for about 3 hours. The excess solvent is removed by reducing the atmospheric pressure by vaccan advantageouslybe usedin the treatment of .cotton .fabric in the manner hereinafter described, but it will be understood that the-manufacture of viscose by this exact method is'not essential.

. n'to the fabric.

The treatment of the cotton fabric, according to "the-present invention, will be further illustrated by describing the treatment of cotton damask with the viscose solution produced in accordance with the above example; but it will be ,understood that this specific procedure is intended as illustrative of the invention, and that the invention is not-limited thereto.

The cotton damask is thoroughly desized memes moved, leaving only such an amount of viscose on and in the fabric as is desired for conversion, by precipitation or decomposition, into cellulose. It will also be seen that the treatment of the fabric with theviscose solution is followed by a drying and the decomposition of the viscose after the,

calendering operation; for example, baths containing acld or acid salts or combinations thereof, or other materials which pre-,

and preferably singed, following the usual cipitate or decompose the viscose. Precipiprocedure of bleaching, although the actual bleaching opfration may be deferred until afterthe fa ric has been. treated withv the viscose solution and the permanent finish Following these preary operations, the fabric is brought 'to a condition of sensible dryness and is then "treated 'on a man ling device in the open width with the viscose solution containing, for example, from 5% to 10% of cellulose. The' excess is squeezed out, the pressure bein adjusted so that the weight of the fabric 18 increased about or in.

other words so that the permanent increase weight will be frbm say 2. 7) to 5%, de-

pending upon then'ature .of the goods and in'a tentering frame, being stretched to'the' the degree of stiffness degig'ed'in the product.

' The impregnated goo are then carried desired finished width, and are made sensiblydry by being subjectedto'the action of a current of warm dr air, [at a. tem rature n.0t.exceeding 120 and the lengt ofthe frame and conditions of ventilation, being p'roperl sult.

'adj'usted to accom lish this ree goods: are then ca endened 'Wlth more or less pressure according to the ty e of goods-bein handled and are thennwit out prior wa ting passed through a'bath of dilute sulphuric acid 'of stren h equivalenttosay 5% to 10% 11180,, e excess acid is then removed by squeezing-and rmsing and v .theoods' are their thorou my cleansed fr m t e difiicultly soluble. sulp 'de byproducts whicharef'not of pleasing color by thorough treatment hot wateni $ubthei: *g'oods may be, bleached and th g i ordinary cotton fabrics alon 'rchingis not. 11900888 7. I In thetrea im nt of the cotton fabric according to theiabove specific-example, 1t W111 be see'n that the viscosesolutionils a'ppli' d I w iea a mu e tating solutions may be used of the character used in the, manufacture of artificial silk from viscose where the viscose thread or filament is passed into a precipitating 1 bath for convertmgthe viscose into cellulose.

The use of a sulphuric acid bath, however, produces a very insoluble deposit and is advantageous for that reason.

It is not necessary to use an aftertreatment of'thefabric with sodium sulphide or eningagents on damasksan'd other types of cotton fabrics or other highly sized matev rials, but is. distinguished from such starched or sized fabrics by having a permanent finish which forms a unitary and tegral part of the treated fabric andls little damaged, if at, all, by repeated washing according to the normal laundering prac- .tice in which hot alkaline-soap solutions,

bleaching solutions, etc., are used. The precipitated viscose is insoluble and 1s so 1ntimately combined with the cotton fibres that it is substantially unafl'ected by the mechanil cal action of laundering or by: the common laundering solutions, andfl'remalns smooth and flexible even after repeated washings.

i The fabric has asmoothfinish, but this finish is distinguished from that produced by starching' and calendering,-'since the latter is entirely transient and a single laun dering removes it, leaving a loose cotto'n fiabi'ic' of ordinary appearance.

' The new treated fabric is of high whitenes's, has the feel as well as the appearance of linen, is readily wet by water, flexible, and closely similar in appearance to linen fabrics of equivalent texture. The new fabric is also distinguished from stiff, harsh and impervment with a precipitating vious fabrics made by treatment with viscose, since the new fabric is soft and pliable and is readily wetted by water and has much the same feel as well as appearance of linen fabric.

In the process of the invention, by which the new fabric is. produced, it will be seen that a viscose solution of low alkalinity is used, while the drying takes place slowly at a low temperature. The regulation of the alkalinity and temperature, with avoidance of excess alkali and high temperatures, prevents discoloration of the fabric and prevents injuring or tendering the fabric, so that the treated fabric is of superior strength. It will also be seen that the fabric is subjected toa drying and calendering treatmentb'efore the acid treatment, with resulting production of a smooth, lustrous and firmly adhering finish. It Wlll further be seen that no sulphides are used after the acid treatment and hence there is no injury to the finish by such use.

The expression regenerated cellulose as used in the claims covers cellulose hydrate which has been regenerated from viscose. I claim:

' 1. The method Oftreating cotton fabrics,

which comprises impregnating the fabric with a visa-.se. solution of low alkalinity, removing the excess solution and precipitating the cellulose from the 1yisplose by treat- 2. The method of treatlng'cotton fabrics, which comprises impregnating the fabric with viscose of an alkalinity corresponding to less than two moles of caustic alkali to one mole of cellulose, removing the excess solution and precipitating the cellulose from the viscose, substantially as described. 1

3. The method of treating cotton fabrics, which comprises impregnating the fabric with a viscose solution of low alkalinity,

' removing the excess solution, drying the fabric in a current of warm dry airand precipitating with dilute acid, substantially as described. V i

4. The method of treating cotton fabrics, which comprises impregnating the fabric with a viscose solution oflow alkalinity, removing the excess solution, drying the fabric iii a current of warm dry air, precipitating with dilute sulphuri-cacid, removing excess acid and removing sulfides by treatment with water, substantiallysas described. 5. The method of treating cotton fabrics, which comprises impregnating the fabric with a viscosesolution of. low alkalinity, removing the. excess solution, drying the fabric in a current of warm dry air, at

a temperature not exceeding 120 deg. F.,

and precipitating with dilute acid, substantially as described.

6. The method of treating cotton fabrics, which comprises impregnating the fabric with a viscose solution of low alkalinity, rcmoving the excess solution, drying the fabric in a current of warm dry air, at a temperature not exceeding 120 deg. F., precipitating with diluted sulphuric acid, removing excess acid and removing sulfides by treatment with hot water, substantially as described. I

7. The method of treating cotton fabrics, which comprises impregnating the fabric with a viscose solution of low alkalinity, removing the excess solution, drying the fabric in a current of warm dry air, calendering the fabric, and precipitating with dilute acid, substantially as described.

8.*The method of treating cotton fabrics, which comprises impregnating the fabric with a viscose solution of low alkalinity, removing the excess solution, drying the fabric in a current of warm dry air at a temperature not exceeding 120 deg. F., calendering and precipitating "with dilute sulphuric acid substantially as described.

9. The method of treating cotton fabrics, which comprises impregnating the fabric with a viscose solution of low alkalinity, squeezin out the excess solution to an extent suc that the permanent increase in weight of the fabric is about 2 to 5 per cent, drying the fabric in a current of warm dry air, calendering, precipitating with dilute acid, removing .the excess acid and washing out sulfides formed, substantially as described.

10. The method of treating cotton fabrics,

.which comprises impregnating the fabric with .a viscose solution of low alkalinity,

containing about 5 to 10 per cent cellulose, squeezing out the excess until there is an increase of weight of about per cent, drying the fabric in a current of warm dry air, calendering, precipitating with dilute sulphuric acid, removing excess acid and washing out the sulphides formed. I

11. As a new article of manufacture, a cotton fabric having a permanent washable finish of regenerated cellulose, said fabric being flexible and readily wetted by water and having a linen-like finish and feel.

'12. As an article of manufacture, a cotton table damask, having a permanent washable finish of regenerated cellulose, said damask being flexible, readily wetted by pager and having a linen-like finish and 13. As a new, article of manufacture, a cotton fabric having a permanent washable finish of regenerated cellulose the amount of said regenerated cellulose being about 2 to 5% of the weightvof the cotton fabric, said fabric being flexible and readily Wettecl b water and having a linenlike finish and eel.

14. As an article of manufacture, a cotton table damask, having a permanent washton fabric, said damask being flexible, readily Wetted by water and having a linenlike finish and feel. 10

In testimony whereof I aflix my signature.

EDGAR RAYMOND CLARK. 

